Anyone keeping an ear on Tesla today?

[Sunking]

I am typing slowly for you to understand. Any battery can be cascaded. That is not a selling point, just blather.

[SmartElectric]

So what. Any battery can be cascaded.

I was directly responding to "10 kWh is not enough". Obviously. I even directly quoted the post. Perhaps I need to type in larger font size for you? Or a prettier color perhaps?

[Sunking]

The Powerwall can be combined as per:
http://www.teslamotors.com/powerwall

So what. Any battery can be cascaded.

[SmartElectric]

10Kw is barely enough for a very small, efficient off grid house, I generally burn 7Kwh in the winter and 12Kwh (adding the water pumps) in the summer. So the 10Kw may just hold me overnight, but when Joe suburb homeowner has a grid failure and his air conditioned spa shuts off 3 hours later, he's not going to be happy with his Tesla battery

The Powerwall can be combined as per:
http://www.teslamotors.com/powerwall

Multiple batteries may be installed together for homes with greater energy need, up to 90 kWh total for the 10 kWh battery and 63 kWh total for the 7 kWh battery.

[SmartElectric]

safe to assume that the price per KW for utilities is lower than the $300/KW they're charging for the residential systems At $300/KW for utility-scale batteries, there's studies for California and Texas that show batteries are a cheaper alternative to building gas-fired peakers.

You are right, the Tesla Powerpack utility sized system is less than $300.
Must tweeted $250/kWh today:

https://twitter.com/elonmusk/status/594186544174366720

[donald]

Actually, the Warranty has fine print, and in the fine print, is the Givith and Takeith away parts. It likely has a data logger too, since it's got to have thermal management smarts. And somewhere is a DC-Dc converter, does it manage the 400VDC pack voltage to 50V for off grid or what. But it's the data logging that will get 'ya, because it will count the 100%-0% excursions and the ones in-between, and they will get you for the pro-rating and service call labor. (well, that's the way everyone else does warranty).
Even 10Kw is barely enough for a very small, efficient off grid house, I generally burn 7Kwh in the winter and 12Kwh (adding the water pumps) in the summer. So the 10Kw may just hold me overnight, but when Joe suburb homeowner has a grid failure and his air conditioned spa shuts off 3 hours later, he's not going to be happy with his Tesla battery.

http://arstechnica.com/information-t...r-10kwh-units/

Thanks for the link. You would need two 7kwh systems. The 10 kwh only rated at a weekly duty cycle.

The warranty has to be pro rated. I think perhaps a big question is how capacity falls off as it ages.

[rwb1921]

Everyone is missing the most important part of the battery system information:

"The key thing for the Powerwall on the consumer side is it’s beautiful, it fits on the wall, you can put it on the outside wall of your house," Musk told journalists. "It's only about 6 inches thick and a few feet across and a few feet tall."

That sells it without all the unnecessary technical specs, who needs them

My son was texting me last night saying are you getting one.......................

[Mike90250]

As I said, if the two models weigh the same, all of the 7kwh is likely usable and the it is not a 7kwh "battery". It a battery system rated to provide 7kwh daily.

You keep talking like the Tesla product is a battery. It is not. It's a battery system. A BMS, cooling system, and probably a charge controller. Plus some sort of regulation on the output side. Does it have a fan? Heat sinks? You criticize conjecture, and now your guessing at what percent of the weight is battery. If not necessarily a negative if they have formulated a lower density battery compared to their EV product.

If the warranty matches the specs, it doesn't matter if the box contains cat piss and oregano.

Actually, the Warranty has fine print, and in the fine print, is the Givith and Takeith away parts. It likely has a data logger too, since it's got to have thermal management smarts. And somewhere is a DC-Dc converter, does it manage the 400VDC pack voltage to 50V for off grid or what. But it's the data logging that will get 'ya, because it will count the 100%-0% excursions and the ones in-between, and they will get you for the pro-rating and service call labor. (well, that's the way everyone else does warranty).
Even 10Kw is barely enough for a very small, efficient off grid house, I generally burn 7Kwh in the winter and 12Kwh (adding the water pumps) in the summer. So the 10Kw may just hold me overnight, but when Joe suburb homeowner has a grid failure and his air conditioned spa shuts off 3 hours later, he's not going to be happy with his Tesla battery.

http://arstechnica.com/information-t...r-10kwh-units/

[donald]

As I said, if the two models weigh the same, all of the 7kwh is likely usable and the it is not a 7kwh "battery". It a battery system rated to provide 7kwh daily.

You keep talking like the Tesla product is a battery. It is not. It's a battery system. A BMS, cooling system, and probably a charge controller. Plus some sort of regulation on the output side. Does it have a fan? Heat sinks? You criticize conjecture, and now your guessing at what percent of the weight is battery. If not necessarily a negative if they have formulated a lower density battery compared to their EV product.

If the warranty matches the specs, it doesn't matter if the box contains cat piss and oregano.

[Sunking]

Which part?
The 100 kg means the marketing people wanted a weight, and the engineers said we don't have one because it is not finished. So they gave a max estimated weight and rounded to a nice even number.

The same internal capacity means that it is a 10-12kwh system if we were to add up the actual cells. If 7 and 10 were 100% DOD figures, we would see two pack weights.

It's all good, because unlike you, Tesla has actual years of experience building these types of battery systems.

I told you did't have a clue. It means 70 wh/Kg. Even a cheap Chi-Com LiFePo4 has 100 wh/Kg density. It means they are using a very cheap battery with low energy density. The EV batteries run 200 to 240 wh/Kg. Top of the line Pb batteries get 70 wh/Kg.

Tesla does not publish what part of that 7 Kwh is usable. Only meaningful spec they have and it is very poor for a Lithium battery is specific energy is very low of C/3 or 2 Kw continuous, and 3 Kw burst aka C/2. All Lithium batteries I know of can discharge at rates in excess of 1C continuous. They published just enough info to be very suspicious if you know what to look for and you have no idea what to look for.

[donald]

So what does that mean Donald. I bet you have no clue. I give you a hint. It is not good.

Which part?
The 100 kg means the marketing people wanted a weight, and the engineers said we don't have one because it is not finished. So they gave a max estimated weight and rounded to a nice even number.

The same internal capacity means that it is a 10-12kwh system if we were to add up the actual cells. If 7 and 10 were 100% DOD figures, we would see two pack weights.

It's all good, because unlike you, Tesla has actual years of experience building these types of battery systems.

[Sunking]

I'm thinking 7kwh is the actual system capacity. They only gave one weight - 100kg.

So what does that mean Donald. I bet you have no clue. I give you a hint. It is not good.

[donald]

On what do you base your certainty ?

Well, that electricity is metered. The 7kwh system is based on the buyers ROI. Their sales projection would be partly derived from estimating the size of this group. Anyone with a solid net metering contract is not part of this group.

I'm thinking 7kwh is the actual system capacity. I'm thinking the 7 and 10 systems have the same amount of internal storage. They only gave one weight - 100kg.

[Sunking]

I like what they unveiled. The fact that its modular, scalable to 50KwH/rack, w/10 year warranty I don't see anything better out there this year.

It is not out there and there are better already out there.

[hub]

Truth be told... I'm actually awaiting for more news of Enphase's battery system. Last I heard was that it was going to be modular and expandable. Unless the pricing of the batteries are going to be cheap and I can figure out how to add more panels to justified going off grid, I don't see myself using batteries that soon.

I like what they unveiled. The fact that its modular, scalable to 50KwH/rack, w/10 year warranty I don't see anything better out there this year.